They are accused in the murders of Gary and Linda Haas, of Tecumseh, Okla., whose bodies were found with their burned-out recreational trailer near Santa Rosa.

The superseding indictment incorporates the original indictment and adds a notice of special findings under a law that allows the death penalty after consideration of mitigating and aggravating factors for people found guilty of such such an offense.

U.S. Attorney Kenneth Gonzales said earlier the trio could face the death penalty if convicted.